Mining apparatus



Feb. 1 1, 1936; p HOLMES MINING APPARATUS Filed Dec. 29, 1932 6Sheets-Sheet l arty F831. 11, 1936. M, p HOLMES MINING APPARATUS FiiedDec. 29, 1932 6 Sheets-Sheet 2 m Q3 m3 Feb. 11, 1936. M O 2,030,064

MINING APPARATUS Filed Dec. 29, 1932 6 Sheets-Sheet 3 6 fi WW. azzg Feb.11, 1936; M p HOLMES 2,030,064

MINING APPARATUS Filed Dec. 29, 1952 6 Sheets-Sheet -5 Patented Feb. 11,1936 UNITED STATES PATENT ()FFlQE MINING APPARATUS MassachusettsApplication December 29, 1932, Serial No. 649,347

81 Claims.

This invention relates to mining apparatus, and more particularly toimprovements in coal mining apparatus of the wheel mounted, tracksupported and guided, bottom cutting type.

An object of this invention is to provide an improved coal miningapparatus. Another object is to provide an improved coal miningapparatus of the wheel mounted, track supported and guided, bottomcutting type. A further object is to provide, in a mining apparatus ofthe above character, improved adjustable kerf cutting mechanism wherebya kerf may be cut at the level of the inine bottom outside and below thelevel of the mine trackway and in advance of the trackway, in animproved manner. Yet another object is to provide an improved coalmining apparatus having improved kerf cutter driving and adjustingmeans. Still another object of this invention is to provide, in a miningapparatus of the above character. an improved tiltable supportingstructure for the kerf cutting mechanism whereby the kerf cutter may beadjusted to cut on a rolling or uneven bottom or a pitching coal seam.Still another object of this invention is to provide an improved miningapparatus of the Wheel mounted, track supported and guided, bottomcutting type particularly adapted for use in mines having relatively lowhead room, the improved apparatus having an extremely low compactarrangement of parts whereby the vertical dimensions thereof are reducedto a minimum. These and other objects and advantages of the inventionwill, however, hereinafter more fully appear.

In the accompanying drawings there is shown for purposes ofillustration, one form which the invention may assume in practice.

In these drawings,-

Fig. 1 is a plan view of the illustrative embodiment of the improvedmining apparatus.

Fig. 2 is a side elevational view of the mining apparatus shown in Fig.1.

Fig. 3 is an enlarged central, longitudinally extending, verticalsectional view taken substantially on line 3-3 of Fig. 1.

Fig. 4 is a horizontal sectional view taken substantially on line 4 l ofFig. 3.

Fig. 5 is a longitudinally extending vertical sectional view takensubstantially on line 5-5 of Fig. 4.

Fig. 6 is a detail sectional view taken on line 66 of Fig. 3.

Fig. 7 is a detail sectional View taken on line l-{l of Fig. 3, Y 1

Fig. 8 is a detail sectional view taken on line B8 of Fig. '7.

Fig. 9 is an enlarged horizontal sectional view taken substantially online 9-5! of Fig. 2.

Fig. 10 is a detail sectional view taken substantially on line lEJ-Ifiof Figs. 1 and 9.

Fig. 11 is an enlarged plan view of the cutter head shown in Fig. 1,with parts shown in horizontal section to illustrate structural details.

Fig. 12 is a longitudinally extending vertical sectional View takensubstantially on line 12-42 of Fig. 11.

Fig. 13 is a detail sectional view taken on line l3|3 of Fig. 12.

Fig. 14 is a detail view of the control rod shown in Fig. 13.

Fig. 15 is a detail sectional viewtaken on line |5-l5 of Fig. 14.

Fig. 16 is a detail sectional view taken on line l6|6 of Fig. 13.

Fig. 17 is a transverse vertical sectional view taken on line I'|l1 ofFigs. 1 and 3.

Fig. 18 is a detail sectional View taken on line [8-48 of Fig. 17.

Fig. 19 is a detail sectional view taken on line l9-|9 of Fig. 18.

Fig. 20 is a detail sectional view taken on line 2020 of Fig. 19.

Fig. 21 is a horizontal sectional view taken substantially on line 2l-2Iof Fig. 3, with parts 3 omitted to facilitate illustration.

Fig. 22 is a detail sectional view taken on line 2222 of Fig. 21.

In this illustrative embodiment of the invention there is shown a coalmining apparatus of the wheel mounted, track supported and guided,bottom cutting type, generally comprising a selfpropelled base I havingmounted thereon improved adjustable kerf cutting mechanism, generallydesignated 2. The base I is herein in the form of a wheeled truckcomprising a low compact truck frame 3 adjustably mounted, in animproved manner as hereinafter described, on truck Wheels l adapted torun along a usual mine trackway 5 laid on the mine bottom. Mounted onthis truck frame 3 for horizontal swinging movement relative theretoabout a vertical axis at 6 is an arm structure I overhanging the forwardend of the truck and in turn having pivotally mounted thereon at 8 forhorizontal swinging movement relative thereto, the improved kerf cuttingmechanism 2. Carried on the rear end of the truck frame is a motor 9having its power shaft l0 op eratively connected to the mechanisms fordriving the cutting mechanism, for swinging the arm structure and thecutting mechanism about their respective pivots, for adjusting theelevation of and tilting the cutting mechanism and for driving the truckwheels to propel the apparatus, as hereinafter described.

Now referring to the improved kerf cutting mechanism 2, and moreparticularly to the improved cutter driving means, it will be noted thatconnected to and driven by the motor power shaft H3 is an alined shaftll suitably journaled at its forward end within a bearing [2 suitablysupported within a frame l3 herein formed integral with the truck frameand which constitutes the main frame of the cutting mechanism. Keyed tothe forward end of the shaft l i is a bevel pinion M (see Figs. 3 and4), nd this pinion meshes with a large bevel gear 55 keyed to a verticalshaft [6 suitably journaled within the main frame I3 and arranged withits axis coincident with the arm structure pivot. Integral with the gearI is a bevel gear I! meshing with a bevel gear 18 keyed to the rear endof a horizontal shaft l9 herein arranged with its axis extendingradially with respect to the pivotal axis of the arm structure l andsuitably journaled within the arm structure, as shown in Fig. 3. Alinedwith the shaft l9 and connectible thereto in driving relation therewith,is a shaft 28 likewise suitably journaled within the arm structure i andhaving keyed thereto at its forward end, as shown in Fig. 12, a bevelpinion 2!. As shown, the bevel pinion 2i meshes with a large bevel gear22 keyed at 23 to atubular drive shaft 24 suitably journaled within thecutter head frame 25 of the cutting mechanism and herein arranged withits axis alined with the pivotal axis 8 of the kerf cutting mechanism.Keyed at 26 to the reduced hub portion 2! of the tubular shaft 24 is avertical shaft 28 herein formed with longitudinal splineways 29throughout a substantial portion of its length and splined at 30 to theupper end of, and having telescopically arranged therein, a tubularshaft element 35, which has herein formed integral therewith a chainsprocket 32 which engages and drives a. usual endless cutter chain 33mounted for orbital movement about the margin of a usual elongated planecutter bar 34. The clutch for connecting the alined shafts i9 and 29 indriving relation, and which herein constitutes the cutter chain clutch,comprises a shiftablo clutch member 35 having internal teeth interlockedwith clutch teeth 36 formed on the rear end of the shaft 2% andengageable with similar clutch teeth 3? formed on the forward end of theshaft [9. This clutch member isshiftable into its connected or releasedpositions by means of a slidable clutch operating member 38 guidedwithin a longitudinal slot formed within the frame id of the armstructure I. Pivotally connected at M to the member 38 is an operatinghandle d2 having formed thereon a pin as engageable with either of twoapertures 66 formed in the arm frame 40. This pin and these aperturesform a lock for holding the clutch member 35 in either of its twopositions. It will thus be evident that the cutter chain 33 may beoperatively connected in driving relation with the motor 9 or may remainidle, at will.

The cutter bar 3 is mounted on the cutter head frame 25 for swingingmovement therewith about the bar pivot axis 3, and is adjustable intodiffer-- ent elevated positions relative to the cutter head, as will nowbe described. The cutter head 25 s rotatively mounted within bearingsleeves d5 encircling the head and supported by a rigid anable hangermounting 68.

nular frame 46 rigidly secured to the forward end of the arm frame 48and constituting the outer overhanging extremity of the arm structure'5. Formed integral with the cutter head frame 25 are laterallyprojecting guides 4i, ii received in vertical guideways 48, 48 formed onan arcuate frame portion 49 integral with the cutter bar hanger 50. Thisbar hanger is provided with a bearing portion 51 carrying bearingsleeves 5.2 interposed between flanges on the shaft 3! and within whichthe lower end of the latter is ion.- naled, as shown in Fig. 12. Theseguideways 53 are provided with adjustable bearing plates secured byscrews 5% to the guide portions: 55 of the hanger frame 49, as shown inFig. 11. It will thus be seen that the cutter bar 34 is swingable withthe cutter head frame 25 relative to the an nular frame 46 of the armstructure '1, and that the cutter bar may be adjusted into differentelevated positions relative to the cutter head frame by adjustmentthereof along the vertical guides 41, 41.

The mechanism for adjusting the cutter bar vertically along theguideways 417, ll relative to the cutter head frame 25 herein comprisesa spur gear 57 rotatably mounted on the tubular shaft 24 and connectiblein driving relation with the shaft 24 by a multiple disc clutch 58 of ausual design. Herein arranged parallel with the shaft 24, and. likewisesuitably journaled within the cutter head frame 25, is a tubular shaft59 having formed integral therewith at its lower end a nut 6|] havinginternal threads meshing with the external threads of a vertical screw5|. The screw 6| is herein non-rotatable and is pivotally connected at62 at its lower end to a transverse pin 63 supported at is ends withinspaced depending webs 64 integral with the bar hanger support 50. Formedintegral with the shaft 59 is a spur gear 65 meshing with a spur gear 65journaled on a Vertical shaft 61 carried by a swing- I'his hangermounting is provided with an arcuate guiding portion 69 rotatablymounted within an arcuate bearing portion I0 herein formed integral withthe cutter head frame 25, the hanger being mounted to swing horizontallyabout the axis of the tubular shaft 59. As shown in Fig. 13, the spurgear 6'5 meshes with a spur gear H journaled on a vertical shaft 12arranged parallel with the shaft 6? i and likewise mounted within theswingable hanger mounting 68. When the hanger mounting 68 is in theposition as shown in Fig. 13 the spur gears 66, H are both out of meshwith the teeth of the. spur gear Bl, but when the hanger mounting isswung in one direction, the

teeth of the gear 66 are brought into mesh with the gear 51, while whenthe hanger mounting is swung in the opposite direction, the gear ll isbrought into mesh with the gear 5?. It will thus be evident that,depending upon the position of the swingable mounting 53, the gear 65,and consequently the nut 60, may be rotated in one direction or theother, thereby to efiect adjustment of the cutter bar upwardly ordownwardly relative to the cutter head.

The means for applying the clutch 58 and for swinging the mounting 68for the reversing gears will now be described. As shown in Fig. 11,journaled within the cutter head frame 25 is a 1ongitudinally extendingshaft '35 having pivotally mounted thereon at 76 an operating lever H.The inner end of the shaft is transversely slotted at l8, 18 to receivearms F9, 19 integral with a rotatable operating member 8!] hereinarranged surrounding the hub portion 21 of the shaft 24 and supportedfor rotative movement on the upper operating plate SI of the clutch 58.Also formed integral with the member 80 is a tooth-like projection 82fitted within a notch 83 formed on a projection 84 integral with theswingable reverse gear mounting 68. It will thus be seen that when theshaft is moved axially in one direction or the other, the operatingmember 80 is rotated, thereby shifting the reverse gear mounting 98 inone direction or the other to bring either the gear 65 or the gear 'IIin mesh with the drive gear 51. Upon rotative movement of the shaft 15,the sides of the flattened portions 18 act as cams to effect swinging ofthe operating member 89 downwardly about its fulcrum 85, thereby toapply the disc clutch 58. Means is provided for preventing applicationof the clutch 58 prior to meshing engagement of one or the other of thegears 86, II with the gear 51, and comprises arcuate grooves 86 and 81formed on the shaft 15 and connected by a longitudinal groove 88.Cooperating with these grooves is a pin 89 secured to the cutter headframe. When the shaft 15 is in the position shown in Fig. 13, rotativemovement thereof is prevented by the pin 89 engaging the sides of thelongitudinal slot 88. When the shaft 15 is slid either inwardly oroutwardly to bring either the gear 55 or the gear II in meshingengagement with the drive gear 51, the pin is brought into registry withone or the other of the arcuate grooves 88, 81, thereby permittingrotation of the shaft 15 to effect application of the disc clutch 58.

Now referring to the improved mechanism for swinging the arm and cutterbar about their respective pivots, it will be observed that secured tothe vertical shaft I8 above the bevel gear I1 is a worm 99 meshing withand driving in opposite directions worm wheels 9! and 92. These wormwheels are rotatably mounted on parallel shafts 93 and 94, respectively,arranged at opposite sides of the shaft IE, on longitudinally extendingaxes and spaced equidistantly from the axis of the shaft I8. These wormwheels are connectible to the shafts 93 and 94, respectively, bymultiple disc clutches 95 and 96. The shafts 93 and 94 are suitablyjournaied within the'arm frame 49 and are connectible by slidingclutches 91 and 98, respectively, to alined screw shafts 99 and I99.Threadedly engaging the screws 99 and I99 are trunnion nuts I0! and I82,respectively, mounted within longitudinal guideways I93 formed in thearm frame and pivotally connected at I94 and I 95, respectively, topairs of link members I96 and I91. The link members I08 are pivotallyconnected at I 08 to lateral ears I89 formed integral with the rotatablecutter head frame 25, while the link members I91 are pivot allyconnected at I II! to a lug I I I formed integral with a frame memberII2 secured by screws II3 to the main frame I3. Keyed to the shafts 93and 94, respectively, are spur gears I I4 and I I5 meshing with an idlergear H5 suitably rotatably mounted on the rearward portion of the shaftI9. The arm frame 40 is provided with a circular guide flange II'Imounted within an arcuate guideway II 8 formed by the frames l3 and H2,and is supported for rotative movement by a bearing sleeve I I9. The armstructure 1 is guided during its swinging movement relative to the truckframe, by an arcuate guide I29 integral with the front portion of thetruck frame and engaging an arcuate guideway I2! formed on the frame ofthe arm structure. It will thus be seen that when one or the other ofthe clutches 95, 95 is applied and the clutch 91 connected, the screwshaft 99 may be rotated in one direction or the other, thereby to swingthe cutter bar 34 in either direction about its pivot through thetrunnion nut and link connection I91, I86. It will also be seen thatwhen one or the other of the clutches 95, 96 is applied and the clutch98 is connected, the screw shaft I09 may be rotated in one direction orthe other, thereby to elfect swinging of the arm structure 1 in eitherdirection through the sliding trunnion nut and link connection I02, I91.

The operating means for the clutch members 91, 98 comprises, as shown inFig. 10, shipper yokes E25, I engageable with grooves formed on themembers 91 and 98. These clutch members are mounted on a transverseoperating rod I21 slidably and rotatably mounted within the arm frame49. Pivotally connected to the opposite ends of the shaft I21 areoperating levers I28. The shipper yoke I25 is provided with an arcuateslot I29 and a communicating longitudinal slot I 38, while the shipperyoke I28 is provided with similar slots I3I and I32. Projecting withinthese slots in the shipper yokes I25, I28, respectively, and secured tothe shaft I21, are pins I33 and I34. When the pins are in the positionshown in Fig. 10, that is, when the shaft I21 is slid outwardly to theleft, the shipper yoke I25 is connected to the shaft I21 by the pin I33received in the longitudinal slot I39, while the shipper yoke I28 isdisconnected from the shaft I21 by the arcuate slot I3I. When the rod 21is slid into its opposite position, the shipper yoke I28 is connected tothe shaft, while the shipper yoke I25 is disconnected therefrom. Whenthe shaft I21 is in the central position, both pins are engaged withinthe longitudinal slots, thereby connecting both shipper yokes to theoperat: ing shaft. It will thus be seen that the clutches 91, 98 may beindependently or simultaneously connected.

Improved variable speed mechanism is provided for controlling the discclutches 95, 96 so that the arm and bar swinging screws may be operatedat a wide range of speeds between zero and a predetermined maximum. Thisimproved clutch controlling means comprises an operating shaft I35having pivotally connected thereto an operating lever I38, as shown inFigs. 3 and 9. This shaft I35 is threaded at I31 with right and lefthand threads, and is threadedly engaged with a split sleeve formingseparately adjustable nut elements I38 and I39. Engaging collaredportions of these nut elements are levers I40 and I4 I As theconnections between these pivoted levers I49, MI and the operatingelements I42 for each of the disc clutches 95, 98 are identical, thedetailed description of the operating means for the clutch 95 willsuffice for both. Rotatable with the gear 9| is a sleeve I43 (see Fig.21) having formed on its rearward face a cam surface I44 with whichengages a sliding member I45 pivotally connected at I48 to the leverI48. Fulcrumed at I41 against the forward face of the bearing sleeve I49for the rearward end of the shaft 93 is a lever I49, and this lever isengageable with the rear face of the outer race of a ball thrust bearingI59 through which pressure is transmitted to the clutch operating memberI42 to effect application of the clutch 85. The inner end of the leverI49 is pivotally connected at I5I to the eye of a bolt member I52. Thisbolt is slidably guided within a sleeve I52 on which isslidably mounteda trunnion l53 pivotally connected at I54 to the-lever I40. Encirclingthe bolt I52 between the bolt head I55 and a washer I56 abutting therear end of the-sleeve 552*, is a coiled spring I51 which normally urgesthe bolt eye in engagement with the front end of the sleeve. The .boltI52 is threaded within its eye and is adjustable relative thereto tovary the compression of the spring I51 as desired. The sliding orlost-motion connection between the trunnion I53 and the sleeve l52permits adjustment of the lever I40, upon adjustment of the nut I38,without affecting the position of the lever I49, the trunnion sliding onthe sleeve during such adjustment. When the operator rotates the shaftI35 in the proper direction, the control mechanism forthe clutch 96 isoperated to release its respective clutch, while the control mechanismfor the clutch 95 is operated to apply its respective clutch. It willthus be seen that as the cam I44 rotates with the worm wheel 9I, the camacts on the inner end of the slide I 45, moving the latter rearwardlyand thereby swinging the lever I49 and, through the bolt connection,swinging the lever I49 forwardly against the thrust bearing I59 toeffect application of the clutch 95. By adjustment of the screw E31, thelever i 19 may be swung either forwardly or rearwardly to vary theposition of its pivoting point; and as a result, as the cam I44 rotates,the lever I49 is variably swung, thereby varying the intervals ofapplication of the disc clutch 95. By adjustment of the lever i 39 intoa position wherein the slide member I 45 is held continuously againstthe surface of the cam, the disc clutch 95 is constantly applied. Inother words, movement of the slide member I45 to the left in Fig. 21will impart a load to the shipper member I42 which will be determined bythe extent of movement of the bolt I52 and the degree of compression ofthe spring I51. More specifically, rotation of the screw I31 in adirection to effect axial movement of the half nut toward the left inFig. 21, moves the fulcrum of the lever I40 toward the left, and therebymoves the member I45 into engagement with the cam i4 2; and uponrotation of the cam the lever I40 is swung, thereby moving the bolt I52to the left to swing the lever I49 to the right, and thereby load theclutch 95. When the half nut is moved to the left so far that thetrunnion I53 continuously abuts the washer I56 encircling the bolt I52,continuous application of the clutch 95 will be effected and the springI51 will compress during each rotation of the cam an amountsubstantially equal to the full throw of the cam; but since the load ofthe spring is desirably above the minimum necessary to effect powertrans mission through the clutch discs, there will be no release evenwhen the slide I45 is in engagement with the lowermost point in the cam.However, by moving the nut graduated amounts toward the right in Fig.21, the period of drive during each rotation of the cam will beprogressively reduced until the clutch is entirely released and drive isdiscontinued. It will thus be seen that drive of the screws 99 and Ithrough the disc clutches may be effected at any desired speed from itsmaximum speed down to zero, by proper adjustment of the parts.Overloading will be prevented by the presence of the springs I51.

The improved mechanism for effecting truck wheel drive to propel theapparatus along the mine trackway both during cutting and transport,herein comprises a worm I60 (see Fig. 3) formed integral with the shaftI6 below the bevel gear I and meshing with and driving in oppositedirections worm wheels I6I and I62. These worm wheels are journaled onparallel longitudinally extending shafts I63, I64, respectively,arranged at the opposite sides of the shaft I6 and in the samelongitudinally extending vertical planes as the screw shafts 99 and I00.These worm wheels are connected to the shafts by multiple disc clutchesI65, I66, respectively. Keyed to the rear ends of the shafts I63, I64,respectively, are spur gears I61 and I 68 meshing with a spur gear I69journaled on a tubular shaft I10. The shaft I surrounds the shaft IIheretofore described and is clutched at its rearward end at I1I to aworm I12 suitably journaled within a gear and axle housing I13. The wormI12 meshes, as shown in Fig. 17, with a worm wheel I14 connectible by amultiple disc clutch I to a transverse shaft I16 suitably journaledwithin the gear housing I13. The operating means for the clutch I15 comprises a pressure plate I18 with which engages a ball thrust bearingI19. Engageable with the outer race of the ball thrust bearing is ashipper yoke I80 fixed to an operating shaft I8I suitably journaledwithin the gear housing I13. Fixed to the shaft I8I is a suitableoperating lever I82 (see Fig. 3). Keyed to the shaft I16 and driventhereby is a chain sprocket I83 connected by a chain 84 to a chainsprocket I85 keyed to the rear axle I86 to which the rear truck wheels 4are secured. Fixed to the opposite ends of the axle I86 are chainsprockets I81, I81 connected by endless chains I88, I88 to chainsprockets I89, I69 secured to the front truck wheels 4, as shown in Fig.4. Splined to the sleeve I10 is a jaw clutch member I90 having clutchteeth I9I connectible to clutch teeth I92 formed on the gear I69. Theclutch member I90 is also provided with clutch teeth I93 connectible toclutch teeth I94 formed on the bevel pinion I4. The clutch member I90 isoperated by a shipper yoke I95 fixed to a transverse operating shaft I96having a suitable operating handle I91. The disc clutches I65, I66 areeach provided with a variable speed control mechanism, respectivelygenerally designated I98, I99, whereby the disc clutches may be eitherconstantly or intermittently and variably applied to effect variablespeed drive of the shafts I63, I64, and this control mechanism isidentical to that above described in connection with the arm and barswinging screw shafts 99, I00. Therefore, further detailed descriptionof the same is deemed unnecessary. However, in this instance theoperating mechanism for the mechanisms I98, I99 includes a toothed wheel209 keyed to the screw operating shaft, and pivotally mounted on thescrew operating shaft is a lever I carrying a dog 202. This dog isslidably guided at 203 within the lever and is normally held in itsreleased position by a coiled spring 204. Formed at the outer extremityof the lever is a. socket 295 for receiving a spherical member 206formed on an operating rod 201. This operating rod is provided with asuitable handle 208 conveniently located at the side of the truck frame.The spherical member 206 is provided with a cam surface 209 so that whenthe rod 201 is rotated, the dog 202 is slid downwardly into engagementwith the teeth of the member 200. The operator then grasps the handle208 and pulls the rod 201 outwardly to effect swinging of the lever tothereby rotate the screw operating rod of the control mechanism. The dog202 may be released by rotating the spherical'member 206 to bring thecam surface 269 into a position to permit release of the dog. It willthus be seen that the truck wheels may be driven at a high transportspeed directly through the shaft II, bevel pinion I4, clutch I99, sleeveI16 and the worm gearing I12, I14, and at a. relatively w cutting speedthrough the worm gearing I60, I6I, I62, parallel shafts I63, Hi l, spurgears I61, I68 meshing with spur gear I69, and in either of oppositedirections under the control of the disc clutches I65, I66. The lowcutting speed may be varied by regulating the control mechanisms I68,I99 for the disc clutches I65,I66.

As above mentioned, the truck frame is mounted for tilting movement; andto afford-such tiltin movement, the gear housing I13 is provided withbearing portions 2I5, 2I6 mounted within bearing sleeves 2I1 carriedwithin bearing supports 2I8, 259 formed, respectively, on the truckframe and the main frame I3, as shown in Fig. 4. This bearing mountingon the gear housing I13 permits rocking movement of the truck frameabout a longitudinal axis, i. e. the axis of the shaft II. The axlehousing mounting for the truck frame is also provided with journals 226,226 within which the rear axle is rotatably mounted, and these journalsform a pivotal mounting for the truck frame to enable tilting of thetruck frame about a transverse axis, i. e. the axis of the rear axleI86. The improved mechanism for effecting such tilting movement of thetruck frame to vary the angle in altitude of the cutting mechanism,herein comprises shafts 22 I, 2 22 aligned with the shafts I63, I64,respectively, as shown in Fig. 4 and connectible to the latter shafts bysliding toothed clutch members 223 and 226, respectively. These clutchmembers are each operated by a shipper yoke 225 secured to a transverseshaft 226 having a suitable-operating lever 221. These shafts 22 I, 222are suitably journaled within the main frame I3 and have formed thereonscrew shafts 228 and 229, and. these screw shafts are each connected, asshown in Fig. 5, to a nut 230. Pivotally connected at 23I to each nut isa link 232, in turn pivotally connected at 233 to an arm 234. These armsare keyed at 235 to alined shafts 236, 231, respectively, suitablyjournaled within the truck frame, as shown in Fig. 4 Formed integralwith the arms 234 are arms 258 carrying the axles 239, 229,respectively, on which the front truck wheels are journaled. It willthus be seen that when the clutches 223, 224 are connected, the screwshafts 223, 229 may be rotated to effect swinging of the arms, therebytilting the truck frame upwardly about the axis of the rear truck wheelaxle. By releasing one or the other of the clutches 223, 224, one of thearms may be swung while the other is stationary, thereby effectingtilting of the truck fra-me'within its journal 2I5, 2I1 about alongitudinal axis. It is accordingly evident that by suitable adjustmentof the arms carrying the front truck wheels, the truck frame may betilted relative to the horizontal, and as a result the angle in altitudeof the cutter bar may be varied relative to the horizontal, it beingpossible to tilt the cutter bar about transverse and longitudinal axes.The drive chains I88, I88 for the front truck wheels are maintainedunder tension by spring pressed guide plates or shoes 2 -15, 246slidably engaging the upper and lower runs of the chains and maintainedunder tension by coiled springs 241, the spring pressed plates 255, 246maintaining the chains at all times under tension during adjustment ofthe front tilting arms for the truck frame.

Power is supplied to the 'motor 9 through a power conductor cable 250wound upon a cable reel 25I mounted at one side of the truck frame, asshown in Fig. 1. This cable reel is driven to effect winding orunwinding of the power conductor cable as the apparatus moves along thetrackway by a pulley 252 keyed to the shaft I16 (see Fig. 17). Thispulley is connected by a belt 253 to a pulley 254 keyed to the cablereel driving shaft 255. A suitable adjustable pulley 256 engages theupper run of the belt 253 to vary the tension of the belt. Formedinternally within the pulley I52 is a braking surface 251 with which abrake band 258 cooperates. This brake band, as shown in Fig. 18, isformed in segments, and these segments are pivotally connected at 259 toadjusting screws 260 connected to abutments 26I formed on the gearhousing I13. Secured to the ends of the brake segments are operatingelements 262, 262 cooperating to form a conical surface 263 with which aconical operating member 264 cooperates. When the operating member 264is moved inwardly, the operating elements 262, 262 are separated,thereby forcing the brake segments into braking contact with the brakesurface 251. The operating mem. her 264 is actuated by a screw shaft 265threadedly connected within a trunnion nut 266 carried by the gearhousing I13. This shaft is provided with a suitable operating handle261. The operating lever I82 for the disc clutch I of the truck wheeldriving mechanism is so arranged that when the truck wheel brake isapplied, the disc clutch is always released, and vice versa. As shown inFig. 19, the clutch operating lever I82 is arranged directly in the pathof movement of the operating shaft 265 for the brake, so that when thebrake is applied, as in the manner shown, the lever I82 is released.When the screw shaft 265 is moved inwardly to effect release of thebrake operating element 26 the clutch operating lever I82 is engaged bythe shaft and swung outwardly toeifect application of the clutch.

The operation of the improved mining apparatus'is as follows: Theapparatus is propelled along the mine trackway at a high transport speedthrough the high speed drive mechanism including drive shaft II, bevelpinion I4, clutch I99, worm gearing I12, I14 and the chain and sprocketconnections connected to the truck wheels. The direction of high speedtruck wheel drive may be reversed by reversing the motor 9. When theworking face is reached, the clutch 98 is connected, and uponapplication of the disc clutch 96 the screw I08 is rotated, therebyeffecting swinging of the arm structure 1 horizontally relative to thetruck frame, through the trunnion nut and link connection, from thecentral position shown in Fig. l to a position wherein the bar pivotaxis 8 lies outside the trackway. As the arm structure is swunglaterally, the clutch 91 may be connected to effect drive of the screw99, thereby to effect swinging of the cutter bar about its pivot throughthe trunnion nut and link connection in the opposite direction until theparts assume an angularly related position with the tip end of thecutter bar at the right hand rib of the entry. The bar and arm swingingclutches 91, 98 are then disconnected. The bar elevating nut 66 is thenoperated by bringing the proper gears 66, H in mesh with the spur gear51, thereby lowering the cutter bar to a position at the level of themine bottom outside and below the level of the trackway. The clutch I96is then shifted to connect the spur .;advance of the trackway.

gear 169 to the sleeve Hi and upon'application of the slow speed truckdrive controlling clutch i6 5 and application of the friction clutch H5,the truck wheels are driven to propelthe apparatus forwardly along themine trackway at a low speed to sump the cutter bar beneath the coal.After the completion of the sumping cut, the brake 251, 258 is applied,thereby holding the truck wheels stationary, and the arm and barswinging screws 99, I60 are then operated to swing the arm and cutterbar in opposite directions about their respective pivots until theyassume a straight line position, the bar swinging screw thereafter beingdisconnected from the motor and the cutter bar swung about the axis 5 ofthe arm to effect its swinging cut across the coal face in advance ofthe trackway. When the tip end of the cutter bar reaches the left handrib, the cutter bar is swung in the opposite di- ,rection until theparts assume an angularly related position, the arm and bar swingingmechanisms thereafter being disconnected from their drives. Theapparatus is then propelled rearwardly along the mine trackway to effectwith- ;drawal of the cutter bar from beneath the coal.

It will be evident that the arm i and cutter bar 34 may be independentlyor simultaneously swung about their respective pivots at variablecutting speeds under the control of the variable ,i peed controlmechanism for the disc clutches e5, 96 and that the apparatus may bepropelled at a predetermined high transport speed. If it is desired totilt the cutter bar to vary its angle in altitude during the horizontalcutting operation, this may be accomplished by operating the clutches223, 224 controlling the tilting screws 228, 229, it being possible totilt the cutter bar about longitudinal and transverse axes. The cutterbar may be adjusted to cut at different levels simply by operating theelevating screw and nut mechanism 66, E! to raise or lower the cutterbar.

As a result of this invention, it will be noted that an improved wheelmounted, track supported and guided, bottom cutting type miningapparatus is provided, having improved adjustable cutting mechanismwhereby a horizontal kerf may be cut at the level of the mine bottomoutside and below the level of the mine trackway and in It will furtherbe noted that by the provision of the improved bar adjusting andswinging mechanism, it is possible to swing and adjust the bar in animproved manner. It will still further be noted that by the provision,;of the improved tilting mechanism for the cutter bar, the cutter barmay be adjusted to out on uneven or rolling bottom or a pitching coalseam. These and other uses and advantages of the improved miningapparatus will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form whichthe invention may as sume in practice, it will be understood that thisform of the same is shown for purposes of illustration and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a. mining apparatus, a support, a cutter frame mounted on saidsupport for rotation relative thereto about a vertical axis with thebottom of said frame projecting below the bottom of said vsupport andsaid frame having depending vertical guides extending downwardlyfrom'the -up er portion of said support a substantial distance below thebottom of said support, a cutter support mounted on said cutter framefor rotation therewith and adjustable vertically along said guides, akerf cutter carried by said cutter support, and driving means for saidkerf cutter including a cutter driving element arranged with its axiscoincident with the axis of rotation of said cutter frame.

2. In a mining apparatus, a support, a cutte frame mounted on saidsupport for rotation relative thereto about a vertical axis with thebottom of said frame projecting below the bottom of said support andsaid frame having depending vertical guides extending dowardly from theupper portion of said support a substantial distance below the bottom ofsaid support, a cutter support mounted on said cutter frame in planesbelow the bottom of said first support for rotation therewith andadjustabie vertically along said guides, a kerf cutter carried by saidcutter support and swingable horizontally with said cutter support andframe relative to said first support, and driving means for said kerfcutter including a cutter driving element arranged with its axiscoincident with the axis of rotation of said cutter frame.

3. In a mining apparatus, a wheeled truck frame having front and reartruck wheels, an arm pivotally mounted on said truck frame forhorizontal swinging movement relative thereto about a vertical axislocated between the front and rear truck wheel axes, a kerf cutterpivotally mounted on the outer extremity of said arm, and

motor operated devices between the truck frame and the front truckwheels and separately or simultaneously adjustable to effect tilting ofsaid truck frame about longitudinal and transverse axes.

4. In a mining apparatus, a wheeled truck rame having front and reartruck wheels, kerf cutting mechanism thereon, motor operated devicesbetween the front truck wheels and said truck frame and independently orsimultaneously 1 independently swinging said arm and kerf cutter abouttheir respective axes including rectilinearly guided, movable-powerswinging devices,-. one for effecting arm swing and the otherfor-effecting cutter swing and each including a power :element movablerectilinearly of its guiding means dur ing the swinging operation.

6. In a mining apparatus, a portable base, an arm mounted on andoverlying said base and at its outer extremity overhanging said base, akerf cutter pivotally mounted on said overhanging extremity of said arm,motor operated swinging devices carried by said arm for independentlyswinging said arm and kerf cutter about their respective axes andincluding rectilinearly guided, movable power swinging devices, one foreffecting arm swing and the other for effecting cutter swing and eachincluding a power element movable rectilinearly of its guiding meansduring the swinging operation, and a motor carried by said base andrelative to which said arm is swingable for operating said powerswinging devices.

7. In a mining apparatus, a portable base, an arm swingably mounted onand overlying said base and at its forward extremity overhanging saidbase, a kerf cutter pivotally mounted on the overhanging extremity ofsaid arm, motor operated screw and nut devices for independentlyswinging said arm and kerf cutter about their respective pivots, and amotor for actuating both of said devices.

8. In a mining apparatus, a portable base, an

arm swingably mounted on and overlying said base and at its forwardextremity overhanging said base, a kerf cutter pivotally mounted on theoverhanging extremity of said arm, motor operated screw and nut devicescarried by said arm for independently swinging said arm and kerf cutterabout their respective pivots, and a motor for actuating both of saiddevices.

9. In a mining apparatus, a portable base, an arm swingably mounted onand overlying said base and at its forward extremity overhanging saidbase, a kerf cutter pivotally mounted on the overhanging extremity ofsaid arm, motor operated screw and nut devices for independentlyswinging said arm and kerf cutter about their respective pivots, and amotor on said base and relative to which said arm is swingable foractuating said screw and nut devices.

10. In a mining apparatus, a portable base, an arm swingably mounted onand overlying said base and at its forward extremity overhanging saidbase, a kerf cutter pivotally mounted on the overhanging extremity ofsaid arm, motor operated screw and nut devices carried by said arm forindependently swinging said arm and kerf cutter about their respectivepivots, and a motor on said base and relative to" which said arm isswingable for actuating said screw andnut devices.

11. In a mining apparatus, a portable base, but a single arm mounted onand overlying said base and at its outer extremity overhanging saidbase, said arm mounted for but confined to horizontal swinging movementrelative to said base, a kerf cutter pivotally mounted on theoverhanging extremity of said arm and having a support, said armconstituting the sole supporting connection between said base and saidkerf cutter support, a motor on said base and relative to which said armis swingable, and means driven by said motor and including arm and kerfcutter swinging devices mounted on said arm for independently swingingsaid arm and kerf cutter about their respective pivots.

12. In a mining apparatus, a portable base, but a single arm mounted onand overlying said base and at its outer extremity overhanging saidbase, said arm mounted for but confined to horizontal swinging movementrelative to said base, a kerf cutter pivotally mounted on theoverhanging extremity of said arm and adjustable relative to said arminto different elevated positions, said kerf cutter having a support andsaid arm constituting the sole supporting connection between said baseand said cutter support, a motor on said base and relative to which saidarm is swingable, means driven by said motor for independently swingingsaid arm and kerf cutter about their respective pivots, and means drivenby said motor for adjusting said kerf cutter into aforesaid elevatedpositions relative to said arm;

13. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, and motor operated screwand nut devices for independently swinging said frame and kerf cutterabout their respective pivots and common motor operated driving meansfor said devices.

14. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, and motor operated screwand nut devices carried by said frame for independently swinging saidframe and kerf cutter about their respective pivots and common motoroperated driving means for said devices.

15. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, motor operated screw andnut devices for independently swinging said rrame and kerf cutter abouttheir respective pivots, and a motor on said support and relative towhich said frame is swingable for actuating said screw and nut devices.

16. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, motor operated screw andnut devices carried by said frame for independently swinging said frameand kerf cutter about their respective pivots, and a motor on saidsupport and relative to which said frame is swingable for actuating saidscrew and nut devices.

1'7. In a mining apparatus, a portable base, a single rigid horizontalarm swingably mounted on and overlying said base and at its outerextremity overhanging said base, said arm confined to horizontalswinging movement relative to said base, a horizontal kerf cutterpivotally mounted on the overhanging extremity of said arm and having asupport, said arm constituting the sole supporting connection betweensaid base and said cutter support, a motor on said base and relative towhich said arm is swingable for independently swinging said arm and kerfcutter about their respective pivots, and means driven by said motor fortilting said base relative to the horizontal to vary the plane ofswinging movement of said arm.

18. In a mining apparatus, a portable base, a single rigid horizontalarm swingably mounted on and overlying said base and at its outerextremity overhanging said base, said arm confined to horizontalswinging movement relative to said base, a kerf cutter pivotally mountedon the overhanging extremity of said arm and adjustable relative to saidarm into different elevated positions, said kerf cutter having a supportand said arm constituting the sole supporting connection between saidbase and said cutter support, a motor on said base and relative to whichsaid arm is swingable for independently swinging said arm and kerfcutter about their respective pivots and for adjusting said kerf cutterinto aforesaid elevated positions relative to said arm, and means drivenby said motor for tilting said'base with respect to the horizontal tovary the plane of swinging movement of said arm.

19. In a mining apparatus, a portable base, a single rigid horizontalarm swingably mounted on and overlying said base and at its outerextremity overhanging said base, said arm confined to horizontalswinging movement relative to said base, a horizontal kerf cutterpivotally mounted on the overhanging extremity of said arm and having asupport, said arm constituting the sole supporting connection betweensaid base and said cutter support, a motor on said base and relative towhich said arm is swingable for independently swinging said arm and kerfcutter about their respective pivots, and devices driven by said motorfor actuating said kerf cutter and for tilting said base with respect tothe horizontal to vary the plane of swinging movement of said arm.

20. In a mining apparatus, a portable base, a single rigid horizontalarm swingably mounted on and overlying said base and at its outerextremity overhanging said base, said arm confined to horizontalswinging movement relative to said base, a kerf cutter pivotally mountedon the overhanging extremity of said arm and adjustable relative to saidarm into different elevated positions, said kerf cutter having a supportand said arm constituting the sole supporting connection between saidbase and said cutter support, a motor on said base and relative to whichsaid arm is swingable for independently swinging said arm and kerfcutter about their respective pivots and for adjusting said kerf cutterinto aforesaid elevated positions relative to said arm, and devicesdriven by said motor for actuating said kerf cutter and for tilting saidbase with respect to the horizontal to vary the plane of swingingmovement of said arm.

21. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto, the forwardextremity of said arm structure overhanging the forward end of saidbase, a cutter frame pivotally mounted on the outer overhangingextremity of said arm structure for rotation about an axis parallel withthe arm structure axis and having depending vertical guides extendingdownwardly in advance of said base, a cutter support mounted on saidguides for vertical adjustment therealong and swingable with said cutterframe relative to said arm structure, and a kerf cutter carried by saidcutter support, said cutter frame and cutter support being swingablerelative to said arm to swing said kerf cutter about the axis of saidcutter frame.

22. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto, the forwardextremity of said arm structure overhanging the forward end of saidbase, a cutter frame pivotally mounted on the outer overhangingextremity of said arm structure for rotation about an axis parallel withthe arm structure axis and having depending vertical guides extendingdownwardly in advance of said base, a cutter support mounted on saidguides for vertical adjustment therealong and swingable with said cutterframe relative to said arm structure, a kerf cutter carried by saidcutter support, said cutter frame and cutter support being swingablerelative to said arm to swing said kerf cutter about the axis of saidcutter frame, and a motor carried by said base and relative to whichsaid arm structure is swingable for actuating said kerf cutter, forrotating said cutter frame relative to said arm structure and foradjusting said cutter support vertically along said guides.

23. In a mining apparatus, a frame, a swingable arm structure overlyingsaid frame and having at its outer extremity an annular frame portion, acutter frame rotatably mounted on said arm structure and having top andbottom bearing elements journaled on said annular frame portion, acutter support carried by said cutter frame beneath the latter, and akerf cutter carried by said cutter support, said cutter frame and cuttersupport being swingable about the cutter frame axis to swing said kerfcutter about the cutter frame axis.

24. In a mining apparatus, a swingable arm structure having at its outerextremity an annular portion, a cutter frame rotatably mounted on saidarm structure and having top and bottom portions j ournaled on saidannular portion, said outter frame having depending vertical guides, acutter support adjustable vertically along said guides relative to saidcutter frame, and a kerf cutter carried by said cutter support, saidkerf cutter being swingable with said cutter frame and cutter supportabout the cutter frame axis and adjustable along said guides intodifierent elevated positions.

25. In a mining apparatus, a swingable arm structure having at its outerextremity an annular frame portion, a cutter frame rotatably mounted onsaid arm structure and having top and bottom bearing elements journaledon said annular frame portion, a cutter support carried by said cutterframe, a kerf cutter carried by said cutter support, said cutter frameand cutter support being swingable about the cutter frame axis to swingsaid kerf cutter about the cutter frame axis, motor operated means foractuating said kerf cutter including a motor driven shaft. journaled onsaid arm structure, a shaft journaled on said cutter frame and arrangedwith its axis coincident with the cutter frame axis, gearing connectingsaid shafts in driving relation and housed Within said cutter frame anddriving connections between the last mentioned shaft and the kerfcutter, and means driven by said gearing for swinging said cutter frame,cutter support and kerf cutter about the cutter frame axis.

26. In a mining apparatus, a swingable arm structure having at its outerextremity an annular portion, a cutter frame rotatably mounted on saidarm structure and having top and bottom portions journaled on saidannular portion, said cutter frame having depending vertical guides, acutter support adjustable vertically along said guides relative to saidcutter frame, a kerf cutter carried by said cutter support, said kerfcutter being swingable with said cutter frame and cutter support aboutthe cutter frame axis and adjustable along said guides into differentelevated positions, and motor operated devices for actuating said kerfcutter including a motor driven shaft journaled on said arm structure, atelescopic torque shaft journaled on said cutter frame and cuttersupport and arranged with its axis coinci-' dent with the cutter frameaxis, gearing connecting said shafts in driving relation and arrangedwithin said cutter frame, and driving connections between said torqueshaft and the kerf cutter.

27. Ina mining apparatus, a swingable arm structure having at its outerextremity an annular portion, a cutter frame rotatably mounted on saidarm structure and having top and bottom portions journaled on saidannular portion, said cutter frame having depending vertical guides, acutter support adjustable vertically along said guides relative to saidcutter frame, a kerf cutter carried by said cutter support, said kerfcutter being swingable with said cutter frame and cutter support aboutthe cutter frame axis and adjustable along said guides into differentelevated positions, motor operated devices for actuating said kerfcutter including a motor driven shaft journaled on said arm structure, atelescopic torque shaft journaled on said cutter frame and cuttersupport and arranged with its axis coincident with the cutter frameaxis, gearing connecting said shafts in driving relation and arrangedwithin said cutter frame, driving connections between said torque shaftand the kerf cutter, and means for adjusting said cutter supportvertically along said guides including adjusting devices driven by saidgearing.

28. In a mining apparatus, a swingable arm structure, a cutter framepivotally mounted on said arm structure for rotation about an axisparallel with the arm structure axis, a cutter support carried by saidcutter frame and rotatable with said cutter frame about the cutter frameaxis, a kerf cutter carried by said cutter support, motor operated meansfor actuating the kerf cutter including a motor driven shaft journaledon the arm structure, a shaft journaled on the cutter frame and arrangedwith its axis coincident with the cutter frame axis, gearing connectingsaid shafts in driving relation and arranged within the cutter frame anddriving connections between said last mentioned shaft and the kerfcutter, and means driven by said gearing for swinging said cutter frame,cutter support and kerf cutter about the cutter frame axis.

29. In a mining apparatus, a swingable arm structure, a cutter framerotatably mounted on said arm structure about an axis parallel with thearm structure axis, said cutter frame having vertical guides, a cuttersupport mounted on said cutter frame for adjustment vertically alongsaid guides, a kerf cutter carried by said cutter support, said cutterframe and cutter support being rotatable about the cutter frame axis toswing the kerf cutter about the cutter frame axis, and motor operateddevices for actuating the kerf cutter including a motor driven shaftjournaled on the arm structure, a telescopic torque shaft journaled onthe cutter frame and cutter support and arranged with its axiscoincident with the cutter frame axis, gearing connecting said shafts indriving relation and arranged within said cutter frame, and drivingconnections between said torque shaft and the kerf cutter.

30. In a mining apparatus, a swingable arm structure, a cutter framerotatably mounted on said arm structure about an axis parallel with thearm structure axis, said cutter frame having vertical guides, a cuttersupport mounted on said cutter frame for adjustment vertically alongsaid guides, a kerf cutter carried by said cutter support, said cutterframe and cutter support being rotatable about the cutter frame axis toswing the kerf cutter about the cutter frame axis, motor operateddevices for actuating the kerf cutter including a motor driven shaftjournaled on the arm structure, a telescopic torque shaft journaled onthe cutter frame and cutter support and arranged with its axiscoincident with the cutter frame axis, gearing connecting said shafts indriving relation and arranged within said cutter frame, drivingconnections between said torque shaft and the kerf cutter, and means foradjusting said cutter support vertically along said guides includingadjusting devices driven by said earing.

31. In a mining apparatus, a swingable arm structure, a cutter framerotatably mounted on said arm structure about an axis parallel with thearm structure axis, said cutter frame having vertical guides, a cuttersupport mounted on said cutter frame for adjustment vertically alongsaid guides, a kerf cutter carried by said cutter support, said cutterframe and cutter support being rotatable about the cutter frame axis toswing the kerf cutter about the cutter frame axis, motor operateddevices for actuating the kerf cutter including a motor driven shaftjournaled on the arm structure, a telescopic torque shaft journaled onthe cutter frame and cutter support and arranged with its axiscoincident with the cutter frame axis, gearing connecting said shafts indriving relation and arranged within said cutter frame, drivingconnections between said torque shaft and the kerf cutter, and means foradjusting said cutter support vertically along said guides includingadjusting devices driven by said gearing, said adjusting devicesincluding a vertical screw connected at its lower end to the cuttersupport, and a cooperating rotatable nut journaled on said cutter frame.

32. In a mining apparatus, a swingable arm structure, a cutter framerotatably mounted on said arm structure about an axis parallel with thearm structure axis, said cutter frame having vertical guides, a cuttersupport mounted on said cutter frame for adjustment vertically alongsaid guides, a kerf cutter carried by said cutter support, said cutterframe and cutter support being rotatable about the cutter frame axis toswing the kerf cutter about the cutter frame axis, motor operateddevices for actuating the kerf cutter including a motor driven shaftjournaled on the arm structure, a telescopic torque shaft journaled onthe cutter frame and cutter support and arranged with its axiscoincident with the cutter frame axis, gearing connecting said shafts indriving relation and arranged within said cutter frame, drivingconnections between said torque shaft and the kerf cutter, and means foradjusting said cutter support vertically along said guides includingadjusting devices driven by said gearing, said adjusting devicesincluding a vertical screw connected at its lower end to the cuttersupport, a cooperating rotatable nut journaled on said cutter frame, andgearing connecting said nut in driving relation with said firstmentioned gearing including a gear element formed on the nut, a gearelement coaxial with the torque shaft, and gearing meshing with said twolast mentioned gear elements.

33. In a mining apparatus, a cutter frame having vertical guides, acutter support mounted on said guides for adjustment verticallytherealong, a kerf cutter carried by said cutter support, motor operatedmeans for actuating the kerf cutter including a rotatable driving memberjournaled in said cutter frame, a telescopic torque shaft journaled insaid cutter frame and cutter support, said torque shaft arrangedcoaxially with and driven by said driving member, and a drivingconnection between said torque shaft and said kerf cutter, and means foradjusting said cutter support along said guides relative to said cutterframe including adjusting devices separate and distinct from said torqueshaft and having driving means driven by said driving member, saiddriving means for said adjusting means including a driving membercoaxial with and rotatable relative to said first mentioned drivingmember, a driving connection between said last mentioned driving memberand. said adjusting devices, and a clutch for connecting said secondmentioned driving member to said first mentioned driving member forrotation with the latter.

34. In a mining apparatus, a cutter frame having vertical guides, acutter support mounted on said guides for adjustment verticallytherealong, a kerf cutter carried by said cutter support, mo-

tor operated means for actuating the kerf cutter including a rotatabledriving member journaled in said cutter frame, a telescopic torque shaftjournaled in said cutter frame and cutter support, said torque shaftarranged coaxially with and driven by said driving member, and a drivingconnection between said torque shaft and "said kerf cutter, and meansfor adjusting said cutter support along said guides relative to saidcutter frame including adjusting devices separate and distinct from saidtorque shaft and having driving means driven by said driving member,said adjusting devices including a vertical screw connected at its lowerend to the cutter support.

and a cooperating rotatable nut journaled in said cutter frame, saiddriving means for adjusting means including a driving member coaxialwith and rotatable relative to said first mentioned driving member, adriving connection tween said last mentioned driving member and saidadjusting devices, and a clutch for connecw ing said second mentioneddriving member to said first mentioned driving member for rotation withthe latter.

35. In a mining apparatus, a cutter frame haw ing vertical guides, acutter support mounted on said guides for adjustment verticallytherealong, a kerf cutter carried by said cutter suppoi motor operateddevices for actuating the kerf cut ter including a telescopic torqueshaft journaled in said cutter frame and said cutter support, a gearcoaxial with said torque shaft for driving the latter, and drivingconnections between said torque shaft and the kerf cutter, and means foradjusting the cutter support along said guides relative to said cutterframe including adjusting devices driven by said gear, said adjustingdevices including a vertical screw connec'ed at its lower end to thecutter support, and a cooperating rotatable nut journaled in said cutterframe and gearing driven by said gear for rotating said nut including agear coaxial with the torque shaft, a gear formed on said rotatable nut,and gearing meshing with said gears.

36. In a mining apparatus, a cutter frame having vertical guides, acutter support mounted on said guides for adjustment verticailytherealong, a kerf cutter carried by said cutter support, motor operateddevices for actuating the kerf cutter including a motor driven shaftjournaled in said cutter frame, a telescopic torque shaft journal-ed insaid cutter frame and said cutter support, gearing connecting saidshafts in driving relation and driving connections between said torqueshaft and the kerf cutter, and means for adjusting said cutter supportalong said guides relative to said cutter frame including adjustingdevices driven by said gearing, the driving connections between saidgearing and said adjusting devices including reversing means wherebywhile said gearing operates continuously in the same direction theadjusting devices may be operated in either of opposite directions.

37. In a mining apparatus, a support, a swingable frame mounted on saidsupport, a cutter frame pivotally mounted on said frame to about an axisparallel with the swingable frame axis, and motor operated devices forswinging said frames about their respective axes includ ing parallelscrews journaled on said swingable frame, means for rotating saidscrews, nuts cooperating with said screws respectively and guided bysaid swingable frame, and links pivotally connected to said nutsrespectively and respectively to said cutter frame and support.

38. In a mining apparatus, a support, a swingable frame adjustablymounted thereon, a cutter frame rotatably mounted on said swingableframe, and means for swinging said frames about their respective axesincluding parallel guideways formed on said swingable frame, elementsreciprocable in said guidesways, means for reciprocating said elements,and links pivotally connected to said reciprocable elements respectivelyand respectively connected to said cutter frame and support.

39. In a mining apparatus, a wheel supported truck frame adapted to runalong a mine trackway and having front and rear truck wheels, horizontalkerf cutting mechanism carried by said truck frame, and means fortilting said truck frame about transverse and longitudinal axes relativeto a horizontal plane including the truck wheel axes including an axlemounting for the rear truck wheels and with which said truck frame haspivotal connection about a longitudinal axis, separate axle mountingsfor the front truck wheels, arms pivotally connected to said front axlemountings and swingably mounted on the truck frame about axes 'oifsetfrom the truck wheel axes, and separate adjusting means forindependently swinging saidarms.

40. In a mining apparatus, a wheel supported truck frame adapted to runalong a mine track- Way and having front and rear truck wheels,horizontal kerf cutting mechanism carried by said truck frame, and meansfor tilting said truck frame about transverse and longitudinal axesrelative to ahorizontal plane including the truck wheel axes includingan axle mounting for the rear truck wheels and with which said truckframe has pivotal connection about a longitudinal axis, separate axlemountings for the front truck wheels, arms pivotally connected to saidfront axle mountings and swingably mounted on the truck frame about axesoffset from the truck wheel axes, and separate adjusting means forindependently swinging said arms including adjusting devices havingrelatively reciprocable adjusting elements carried by said truck frame,one adjusting device for actuating each arm.

41. In "a mining apparatus, a wheel supported truck frame adapted to runalong a mine trackway and having front and rear truck wheels, horizontalkerf-cutting-mechanism carried by said truck frame, and means fortilting said truck frame about transverse and longitudinal axes relativeto a horizontal plane including the truck wheel axes including an axlemounting for the rear truck wheels and with which said truck frame haspivotal connection about a longitudinal-axis, separate axle mountingsfor the front truck wheels, arms pivotally connected to said front axlemountings and swingably mounted on the truck frameabout axes offset fromthe truck Wheel axes, and separate adjusting means for independentlyswinging said arms including adjusting devices carried by said truckframe, one for actuating each arm, said devices each including are'ctilinearly movable adjusting element and a cooperating element, anarm swingable with said truck wheel axle mounting arm, and a linkconnecting said last mentioned arm and said rectilinearly movableelement.

42. In a mining apparatus, a wheel supported truck frame adapted to runalong a mine trackway and having front and rear truck wheels, horizontalkerf cutting mechanism carried by said truck frame, and means fortilting said truck frame about transverse and longitudinal axes relativeto a horizontal plane including the truck wheel axes including an axlemounting for the rear truck wheels and with which said truck frame haspivotal connection about a longitudinal axis, separate axle mountingsfor the front truck wheels, said front axle mountings each havingindependent adjustable mountings on the truck frame, and independentadjusting means for adjusting said front axle mountings.

43. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto: about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure and adjustable relative thereto, motor operated kerfcutter actuating means including a motor driven shaft journaled on saidbase, a shaft journaled on said base and arm structure and arranged withits axis coincident with the arm structure pivot axis, gearingconnecting said shafts in driving relation, shafting journaled on saidarm structure and. driven by said gearing, a shaft arranged with itsaxis coincident with the kerf cutter pivot axis and gearing connectingsaid shafting and said last mentioned shaft in driving relation, andmeans driven by said last mentioned gearing for adjusting said kerfcutter relative to said arm structure and including a shaft parallelwith said last mentioned shaft.

44. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base toswing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on and adjustablerelative to the outer extremity of said arm structure, and motoroperated kerf cutter actuating means including a motor driven shaftjournaled on said base, a shaft 'journaled on said I base and armstructure and arranged with its axis coincident with the arm structurepivot axis, gearing connecting said shafts in driving relation, shaftingjournaled on said arm structure and driven by said gearing, a shaftarranged with its axis coincident with the kerf cutter pivot axis,gearing connecting said shafting and said last mentioned shaft indriving relation, means driven by said second mentioned shaft forswinging said arm structure relative to said base, and means driven bysaid last mentioned gearing for adjusting said kerf cutter relative tosaid arm structure.

45. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure, and motor operated kerf cutter actuating meansincluding a motor driven shaft journaled on said base, a shaft journaledon said base and arm structure and arranged wiih its axis coincidentwith the arm structure pivot axis, gearing conn cting said shafts indriving relation, shafting journaled on said arm structure and driven bysaid gearing, a shaft arranged with its axis coincident with the kerfcutter pivot axis, and gearing connecting said shafting and said lastmentioned shaft in driving relation, means driven by said secondmentioned shaft for swinging said arm structure relative to said baseand for swinging said kerf cutter relative to said arm structure, andmeans driven by said last mentioned gearing for adjusting said kerfcutter relative to said arm structure.

46(In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer exterrnityof said arm structure, motor operated kerf cutter actuating meansincluding a motor driven shaft journaled on said base, a shaft journaledon said base and arm structure and arranged with its axis coincidentwith the arm structure pivot axis, gearing connecting said shafts indriving relation, shafting journaled on said arm structure and driven bysaid gearing, a shaft arranged with its axis coincident with the kerfcutter pivot axis, and gearing connecting said shafting and said lastmentioned shaft in driving relation, and means driven by saidsecondmentioned shaft for tilting said base relative to the horizontal.

4'7. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure, motor v operated kerf cutter actuating meansincluding a motor driven shaft journaled on said base, a shaft journaledon said base and arm structure and arranged with its axis coincidentwith the arm structure pivot axis, gearing connecting said shafts indriving relation, shafting journaled on said arm structure and driven bysaid gearing, a shaft arranged with its axis coincident with the kerfcutter pivot axis, and gearing connecting said shafting and said lastmentioned shaft in driving relation, means driven by said secondmentioned shaft for swinging said arm structure relative to said base,and means driven by said second mentioned shaft for tilting said baserelative to the horizontal.

48. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf'cutter pivotally mounted on the outer extremity ofsaid arm structure, motor operated kerf cutter actuating means includinga motor driven shaft journaled on said base, a shaft journale-d on saidbase and arm structure and arranged with its axis coincident with thearm structure pivot axis, gearing connecting said shafts in drivingrelation, shafting journaled on said arm structure and driven by saidgearing, a shaft arranged with its axis coincident with the kerf cutterpivot axis, and gearing connecting said shafting and said last mentionedshaft in driving relation, means driven by said second mentioned shaftfor swinging said arm structure relative to said base and for swingingsaid kerf cutter relative to said arm structure, and means driven bysaid second mentioned shaft for tilting said base relative to thehorizontal.

49. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure, motor operated kerf cutter actuating means includinga motor driven shaft journaled on said base, a shaft journaled on saidbase and arm structure and arranged with its axis coincident with thearm structure pivot axis, gearing connecting said shafts in drivingrelation, shafting journaled on said arm structure and driven by saidgearing, a shaft arranged with its axis coincident with the kerf cutterpivot axis, and gearing connecting said shafting and said last mentionedshaft in driving relation, means driven by said last mentioned gearingfor adjusting said kerf cutter relative to said arm structure andincluding a shaft parallel with said last mentioned shaft, and meansdriven by said first mentioned shaft for propelling said base.

50. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on and adjustablerelative to the outer extremity of said arm structure, motor operatedkerf cutter actuating means including a motor driven shaft journaled onsaid base, a shaft journaled on said base and arm structure and arrangedwith its axis coincident with the arm structure pivot axis, gearingconnecting said shafts in driving relation, shafting journaled on saidarm structure and driven by said gearing, a shaft arranged with its axiscoincident with the kerf cutter pivot axis, and gearng connecting saidshafting and said last mentioned shaft in driving relation, means drivenby said second mentioned shaft for swinging said arm structure relativeto said base, means driven by said last mentioned gearing for adjustingsaid kerf cutter relative to said arm structure, and means driven bysaid first mentioned shaft for propelling said base.

51. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on and adjustablerelative to the outer extremity of said arm structure, motor operatedkerf cutter actuating means including a motor driven shaft journaled onsaid base, a shaft journaled on said base and arm structure and arrangedwith its axis coincident with the arm structure pivot axis, gearingconnecting said shafts in driving relation, shafting journaled on saidarm structure and driven by said gearing, a shaft arranged with its axiscoincident with the kerf cutter pivot axis, and gearing connecting saidshafting and said last mentioned shaft in driving relation, means drivenby said second mentioned shaft for swinging said arm structure relativeto said and for swinging said kerf cutter relative to said armstructure, means driven by said last mentioned gearing for adjustingsaid kerf cutter relative to said arm structure, and means driven bysaid first mentioned shaft for propelling said base.

52. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure, motor operated kerf cutter actuating means includinga motor driven shaft journaled on said base, a shaft journaled on saidbase and arm structure and arranged with its axis coincident with thearm structure pivot axis, gearing connecting said shafts in drivingrelation, shafting journaled on said arm structure and driven by saidgearing, a shaft arranged with its axis coincident with the kerf cutterpivot axis, and gearing connecting said shafting and said last mentionedshaft in driving relation, means driven by said second mentioned shaftfor tilting said base relative to the horizontal, and means driven bysaid first mentioned shaft for propelling said base.

53. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure, motor operated kerf cutter actuating means includinga motor driven shaft journaled on said base, a

shaft journaled on said base and arm structure and arranged with itsaxis coincident with the arm structure pivot axis, gearing connectingsaid shafts in driving relation, shafting journaled on said armstructure and driven by said gearing, a shaft arranged with its axiscoincident with the kerf cutter pivot axis, and gearing connecting saidshafting and said last mentioned shaft in driving relation, means drivenby said second mentioned shaft for swinging said arm structure relativeto said base, means driven by said second mentioned shaft for tiltingsaid base relative to the horizontal, and means driven by said firstmentioned shaft for propelling said base.

54. In a mining apparatus, a portable base, an arm structure pivotallymounted on said base to swing horizontally relative thereto about avertical axis, a kerf cutter pivotally mounted on the outer extremity ofsaid arm structure, motor operat'ed kerf cutter actuating meansincluding a motor driven shaft journaled on said base, a shaft journaledon base and arm structure and arranged with its axis coincident with thearm structure pivot axis, gearing connecting said said shafting and saidlast mentioned shaft in driving relation, means driven by said secondmentioned shaft for swinging said arm structure relative to said baseand for swinging said kerf cutter relative to said arm structure, meansdriven by said second mentioned haft for tilting said base relative tothe horizontal, and means driven by said first mentioned shaft forpropelling said base.

55. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, and motor operateddevices for independently swinging said frame and kerf cutter abouttheir respective pivots comprising separate adjusting devices eachincluding relatively rotatable and axially movable meill chanicallyinterlocking adjusting elements, said elements being self -locking forholding the frame and kerf cutter in adjusted position.

56. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, and motor operateddevices carried by said frame for independently swinging said frame andkerf cutter about their respective pivots comprising separate adjustingdevices each including relatively rotatable and axially movablemechanically interlocking adjusting elements, said elements beingself-locking for holding the frame and kerf cutter in adjusted position.

57. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame about an axis parallelwith the frame pivot axis, and motor operated devices for independentlyswinging said frame and kerf cutter about their respective pivotscomprising separate adjusting devices each including cooperating motoractuated adjusting elements having relative axial movement.

58. In a mining apparatus, a support, a frame swingably mounted thereon,a kerf cutter pivotally mounted on said frame, and motor operateddevices carried by said frame for independently swinging said frame andkerf cutter about their respective pivots comprising separate adjustingdevices each including cooperating motor actuated adjusting elementshaving relative axial movement.

59. In a mining apparatus, a portable base comprising a low compact baseframe, but a single rigid horizontal arm swingably arranged inrelatively low planes closely adjacent the top of said base frame andconfined to horizontal swinging movement relative to the base frame,said arm overlying said base frame and at its forward extremityoverhanging the forward end of the base frame, vertical depending guidescarried at the outer overhanging extremity of said arm and extendingdownwardly below the top surface of said arm in advance of said base, acutter support ad justable vertically along said guides, said armconstituting the sole supporting connection between said cutter supportand base, a kerf cutter carried by said cutter support, and a motorcarried on said base frame at the rear of said arm and in planes belowthe top surface of said arm and relative to which said arm is swingablefor actuating said kerf cutter and for adjusting said kerf cuttersupport along said guides.

60. In a mining apparatus, a portable base, a horizontally swingable armpivotally mounted on and overlying said base and at its forwardextremity overhanging said base, a cutter frame mounted on the forwardoverhanging extremity of said arm for rotation relative thereto about anaxis parallel with the arm pivot axis, said cutter frame havingdepending vertical guides, a cutter support mounted on said cutter framefor rotative movement therewith relative to said arm and for verticaladjustment relative to said cutter frame along said guides, a kerfcutter carried by said cutter support, mechanism for swinging said armwhile said cutter frame remains stationary as regards rotative movementabout its axis relative to said arm, and mechanism for rotating saidcutter frame relative to said arm while the latter remains stationary asregards swinging movement about its pivotal axis relative to said base,said mechanisms being operative to swing simultaneously said arm andcutter frame about their respective pivotal axes.

61. In a mining apparatus, a portable base, a horizontally swingable armpivotally mounted on and overlying said base and at its forwardextremity overhanging said base, a cutter frame mounted on the forwardoverhanging extremity of said arm for rotation relative thereto about anaxis parallel with the arm pivot axis, said cutter frame havingdepending vertical guides, a cutter support mounted on said cutter framefor rotative movement therewith relative to said arm and for verticaladjustment relative to said cutter frame along said guides, a kerfcutter carried by said cutter support and swingable horizontally withsaid cutter frame and support about the cutter frame axis relative tosaid arm, mechanism for swinging said arm while said cutter frameremains stationary as regards rotative movement about its axis relativeto said arm, and

mechanism for rotating said cutter frame relative to said arm while thelatter remains stationary as regards swinging movement about its pivotalaxis relative to said base, said mechanisms being operative to swingsimultaneously said arm and cutter frame about their respective pivotalaxes.

62. In a mining apparatus, a swingable frame, a cutter frame mounted onsaid frame for rotation relative thereto about a vertical axis andhaving depending vertical guides extending downwardly from the upperportion of said first frame, a cutter support mounted on said cutterframe for rotation therewith relative to said first frame and adjustablevertically relative to said cutter frame along said guides, a kerfcutter carried by said cutter support, mechanism for rotating saidcutter frame relative to said first frame while the latter remainsstationary, mechanism for swinging said first mentioned frame about itspivot while said cutter frame remains stationary as regards rotationrelative to said swingable frame, said mechanisms being simultaneouslyoperable to effect simultaneous rotation of said cutter frame andswinging of said swingable frame, and mechanism for adjusting saidcutter support vertically along said guides and for actuating said kerfcutter.

63. In a mining apparatus, a swingable frame, a cutter frame mounted onsaid frame for rotation relative thereto about a vertical axis andhaving depending vertical guides extending downwardly from the upperportion of said first frame, a cutter support mounted on said cutterframe for rotation therewith relative to said first frame and adjustablevertically relative to said cutter frame along said guides, a kerfcutter carried by said cutter support and swingable horizontally withsaid cutter support and cutter frame relative to said first frame,mechanism for rotating said cutter frame relative to said first framewhile the latter remains stationary, mechanism for swinging said firstmentioned frame about its pivot while said cutter frame remainsstationary as regards rotation relative to said swingable frame, saidmechanisms being simultaneously operable to effect simultaneous rotationof said cutter frame and swinging of said swingable frame, and mechanismfor adjusting said cutter support vertically along said guides and foractuating said kerf cutter.

64. In a mining apparatus, a portable base,

a horizontally swingable arm pivotally mounted on and overlying saidbase and at its forward extremity overhanging said base, a cutter framemounted on the forward overhanging extremity of said arm for rotationrelative thereto: about an axis parallel with the arm pivot axis andhaving depending vertical guides, a cutter support mounted on saidcutter frame for vertical adjustment along said guides, a kerf cuttercarried by said cutter support and having orbitally movable cuttingmeans, the pivotal axis of said cutter frame lying within the orbit ofsaid cutting means, and a motor on said base and relative to which saidarm is swingable for actuating said kerf cutter, for swinging said arm,for rotating said cutter frame and for adjusting said cutter supportalong said guides.

65. In a mining apparatus, a portable base, a horizontally swingable armpivotally mounted on and overlying said base and at its forwardextremity overhanging said base, a cutter frame mounted on the forwardoverhanging extremity of said arm for rotation relative thereto about anaxis parallel with the arm pivot axis and having depending verticalguides, a cutter support mounted on said cutter frame for verticaladjustment along said guides, a kerf cutter carried by said cuttersupport and having orbitally movable cutting means, the pivotal axis ofsaid cutter frame lying within the orbit of said cutting means, saidkerf cutter swingable horizontally with said cutter support and cutterframe about the axis of the latter relative tosaid arm, and a motor onsaid base and relative to which said arm is swingable for actuating saidkerf cutter, for

and for adjusting said cutter support along its guides.

66. In a mining apparatus, a frame, a cutter frame mounted on said framefor rotation relative thereto about a vertical axis and having dependingvertical guides extending downwardly from the upper portion of, saidfirst frame, a cutter support mounted on said cutter frame in planesbelow the bottom of said first frame for rotation with said cutter frameand adjustable vertically relative to said cutter frame along saidguides, and a kerf cutter carried by said cutter support and swingablehorizontally with said support and cutter frame relative to said firstframe, said kerf cutter having orbitally movable cutting means and thepivotal axis of said outter frame lying within the orbit of said cuttingmeans.

67. In a mining apparatus a wheeled truck frame, kerf cutting mechanismon said truck frame, and motor operated devices between the truck frameand the front truck wheels and separately or simultaneously adjustableto effect tilting of said truck frame about longitudinal and transverseaxes to vary the angular cutting position of said kerf cuttingmechanism, said adjusting devices for each front truck wheel including arectilinearly guided, movable element, a connection between said movableelement and the truck wheels, and power operated means for moving saidelement rectilinearly of its guiding means.

68. In a mining apparatus, a portable base, an arm pivotally swingablymounted on and overlying said base and at its forward extremityoverhanging said base, a kerf cutter pivotally mounted on the forwardoverhanging extremity of said arm, motor operated means forindependently swinging said arm and kerf cutter about their respectivepivots including separate means individual to said arm and kerf cutterand each including a rectilinearly guided, movable element, a connectionbetween said movable element and the element swung thereby and poweroperated means for moving said element rectilinearly of its guidingmeans, and a motor on said base and relative to which said arm isswingable for operating said elements.

69. In a mining apparatus, a portable base, an arm pivotally swingablymounted on and overlying said base and at its forward extremityoverhanging said base, a kerf cutter pivotally mounted on the forwardoverhanging extremity of said arm, motor operated means carried by saidarm for independently swinging said arm and kerf cutter about theirrespective pivots and including for said arm and kerf cutter separateadjusting means including for each a rectilinearly guided, movable powerswinging device carried by said arm, and a motor on said base relativeto which said arm is swingable for operating said power swingingdevices.

70. In a mining apparatus, a portable base, an arm pivotally mounted onsaid base to swing horizontally relative thereto about a vertical axis,a kerf cutter pivotally mounted on the outer extremity of said arm toswing relative thereto about a parallel axis, said kerf cutter beingadjustable vertically into different elevated positions with respect tosaid arm and said arm being tiltable with respect to the horizontal,rectilinearly guided, movable power devices for tilting said arm,rectilinearly guided, movable power devices for swinging said arm andkerf cutter swinging said arm, for rotating said cutter framev abouttheir respective pivots, a rectilinearly movable power device foradjusting said kerf cutter into different elevated positions withrespect to said arm, and a motor on said base and relative to which saidarm is swingable for operating said power devices.

'71. In a mining apparatus, a frame, a kerf cutter pivotally mounted onsaid frame, and mechanism for swinging said kerf cutter about its pivotincluding a screw, a nut threadedly connected to said screw to traveltherealong, a link pivotally connecting said nut to said kerf cutter,and motor operated devices for rotating said screw through a wide rangeof speeds including a driving element coaxial with said screw, a clutchfor connecting said driving element in driving relation with said screw,and means actuated by said driving element for automaticallyintermittently applying and releasing said clutch at varying intervals.

'72. In a mining apparatus, a portable base, an arm pivotally mounted onsaid base to swing horizontally relative thereto, a kerf cutterpivotally mounted on the outer extremity of said arm, and motor operatedmeans for swinging said arm about its pivot through a wide range ofspeeds including a friction clutch and means for automaticallyintermittently applying and releasing said clutch, and means forswinging said kerf cutter about its pivot through a wide range of 7speeds including a friction clutch and means for automaticallyintermittently applying and releasing said clutch, said arm and kerfcutter swinging means including driving elements coaxial with saidclutches respectively and by which said clutch applying and releasingmeans are respectively actuated.

73. In a mining apparatus, a portable base of relatively low overallheight, a'horizontal kerf cutter, means for swingably supporting saidkerf cutter on said base comprising but a single rigid horizontal armmounted on and disposed in horizontal planes closely adjacent the top ofsaid base in overlying relation with respect to the latter, said rigidarm at its forward extremity overhanging the forward end of said baseand swingable horizontally relative to said base about a vertical axis,said horizontal kerf cutter pivotally mounted on the forward overhangingextremity of said rigid arm, a motor on said base at the rear of saidarm and relative to which said arm is swingable for independentlyswinging said arm and kerf cutter about their respective pivots, saidmotor disposed within the vertical limits of the apparatus below the topsurface of said arm, and means driven by said motor for tilting saidbase with respect to the horizontal to change the plane of swingingmovement of said arm.

74. In a mining apparatus, a portable base of relatively low overallheight, a horizontal kerf cutter, means for swingably supporting saidkerf cutter on said base comprising but a single rigid horizontal armmounted on and disposed in horizontal planes closely adjacent the top ofsaid base in overlying relation with respect to the latter, said rigidarm at its forward extremity overhanging the front end of said base andswingable horizontally relative to said base about a vertical axis, saidkerf cutter being pivotally mounted on the forward overhanging extremityof said arm and adjustable relative to said arm into different elevatedpositions between the lower surface of said arm and the mine fioor, amotor on said base at the rear of said arm and relative to which saidarm is swingable for independently

